Medication-related osteonecrosis of the jaw: Case series and literature review.

Key Clinical Message: Medication-related osteonecrosis of the Jaw (MRONJ) is a rare complication of the jaws following the administration of antiresorptive or antiangiogenic drugs. This condition poses a major challenge to its management. Its prevention and management need a multidisciplinary collaboration. We described three patients with MRONJ including their presentation, investigations, management protocols, and outcomes. A brief appraisal of the literature on MRONJ was also done. Abstract: Medication-related osteonecrosis of the jaw (MRONJ) is a rare complication of the jaws following the administration of antiresorptive or antiangiogenic drugs. This condition poses a major challenge to its management. We present an appraisal of the literature and three cases of MRONJ. An appraisal of 3 patients who presented to the oral and maxillofacial clinic with MRONJ was done. Relevant physical examination findings, radiological images, clinical photographs and follow-up was documented. One patient had multiple myeloma while the other two had metastatic cancer. All had received zoledronic acid before developing MRONJ. One patient was surgically treated and successfully recovered while two were managed conservatively. Patients taking antiresorptive medications are at risk of developing MRONJ. Prevention and management of the condition calls for a multidisciplinary collaboration. Patients taking antiresorptive medications need good education on the risks associated with the medications and how to recognize early signs and symptoms.

Computed Tomography Scan Assessment of the Anatomy of the Pterygomaxillary Junction and Its Relevance in Le Fort I Osteotomy.

Knowledge of the morphometry and types of pterygomaxillary junction (PMJ) during Le-Fort I osteotomy is an important consideration in the reduction of intraoperative complications. The PMJ is known to display population variations and with the recent increase in these surgical interventions in Kenya, a detailed description of the PMJ is warranted. Computed tomography scan images of PMJ obtained from 63 patients were analyzed at the level of the posterior nasal spine to assess types and the morphometry of the PMJ. A fissure type of PMJ was present in 65.9% (83/126 sides) while a synostosis type was present in 34.1% (43/126). Bilateral fissures were found in 58.73% (37/63), bilateral synostosis in 26.98% (17/63), and an asymmetric PMJ in 15.25% (9/63). The average height, width, and thickness of the PMJ were 17.45 ±â€Š5.26 mm, 10.24 ±â€Š1.97 mm, and 6.40 ±â€Š1.97 mm respectively. Males had a significantly greater height (P = 0.003) and width (P = 0.000). The average width was greater in cases with a synostosis as compared with those with a fissure (P = 0.019). Average distance of greater palatine canal was 40.41 ±â€Š2.28 mm and 7.19 ±â€Š2.20 mm from the piriform rim and the pterygoid fossa respectively. The PMJ among Kenyans is characterized by a higher occurrence of synostosis, greater height, and thickness compared with previous findings from other populations. The results of this study can be helpful for surgeons in selecting the most appropriate techniques to achieve successful pterygomaxillary disjunction and minimize avoid attendant complications such as vascular and nerve injuries.

Variations of the Anatomy and Bony Landmarks of Deep Circumflex Iliac Artery in a Select Kenyan Population.

BACKGROUND: The deep circumflex iliac artery (DCIA) is a large caliber artery which branches laterally from the external iliac artery (EIA), directly opposite the origin of the inferior epigastric artery (IEA). Population variations have been reported in its origin, length, and branching patterns. These may alter its relationship to palpable surgical landmarks such as the anterior superior iliac spine (ASIS) and the pubic tubercle (PT) which are used to locate the artery preoperatively, thus predisposing it iatrogenic injury. Despite this, there is paucity of data from the Kenyan setting. STUDY DESIGN: Cross-sectional study design. OBJECTIVE: To determine the variations of the anatomy and bony landmarks of the Deep circumflex iliac artery in a select Kenyan population. METHODS: A total of 104 DCIA from 52 formalin fixed adult cadavers were dissected to expose the DCIA, following which its vessel of origin and distance from the ASIS and PT, relation to the inguinal ligament (IL), length and branching patterns were noted. The average of the measurements were calculated. All data were collected and analyzed using Microsoft Excel 2007 (Microsoft Corporation, Redmond, WA). Representative photos of the vessel and its variations were taken. RESULTS: The DCIA was found to be present and bilaterally symmetrical in all cadavers. In all cases observed, it originated as a lateral branch from the EIA (100%), opposite the IEA and directly behind the IL in 98% of the cases. Its average distance from the ASIS along the IL was 7.28 ± 0.99, while it was 5.91 ± 1.03 from the pubic tubercle to its origin. Its length ranged from 3.7 cm to 9.5 cm, with an average length of 3.86 cm in the right limb and 3.67 cm in the left limb. As regards its branching patterns, in 78% of the cases, it bifurcated into the horizontal and ascending branches, in 6%, it trifurcated and in 4%, it divided into more than 3, exhibiting a fine tree-like branching (arborization). CONCLUSION: The DCIA in our setting exhibited variations from other settings and an increase in awareness of these variations will probably reduce future iatrogenic lesions of the DCIA and its major branches in Kenya.

The Relation of the Extracranial Spinal Accessory Nerve to the Sternocleidomastoid Muscle and the Internal Jugular Vein.

The spinal accessory nerve (SAN) exhibits variant anatomy in its relation to the internal jugular vein (IJV) as well as the sternocleidomastoid muscle (SCM). These variations are important in locating the nerve during surgical neck procedures to avoid its inadvertent injury. These variations, however, are not conserved among different populations and data from the Kenyan setting are partly elucidated. This study, therefore, aims to determine the variant anatomical relationship of the SAN to the SCM and IJV in a select Kenyan population. Forty cadaveric necks were studied bilaterally during routine dissection and the data collected were analyzed using SPSS version 21. Means and modes were calculated for the point of entry of the SAN into the posterior triangle of the neck as well as for its relation to the SCM. Side variations for both of these were analyzed using Student's t -test. Data relating the SAN to the IJV were represented in percentages and side variations were analyzed using the chi-square test. The SAN point of entry into the posterior triangle of the neck was 5.38 cm (3.501-8.008 cm) on the left side and 5.637 cm (3.504-9.173 cm) on the right side ( p = 0.785) from the mastoid process. The nerve perforated the SCM in four cases (10%) on the left side and in eight cases (20%) on the right ( p = 0.253). The SAN lay predominantly medial to the IJV on both sides of the neck, 87.5% on the left side of the neck versus 82.5% on the right ( p = 0.831). In conclusion, the variant relation of the SAN to the IJV and SCM as observed in this setting is an important consideration during radical neck procedures and node biopsies.

Surgical Anatomy of the Cervical Part of the Hypoglossal Nerve.

Iatrogenic injuries to cranial nerves, half of which affect the hypoglossal nerve, occur in up to 20% of surgical procedures involving the neck. The risk of injury could be minimized by in-depth knowledge of its positional and relational anatomy. Forty-one hypoglossal nerves were dissected from cadaveric specimens and positions described in relation to the internal carotid artery (ICA), external carotid artery (ECA), carotid bifurcation, mandible, hyoid bone, mastoid process, and the digastric tendon. The distance of the nerve from where it crossed the ICA and ECA to the carotid bifurcation was 29.93 (±5.99) mm and 15.19 (±6.68) mm, respectively. The point where it crossed the ICA was 12.24 (±3.71) mm superior to the greater horn of hyoid, 17.16 (±4.40) mm inferior to the angle of the mandible, and 39.08 (±5.69) mm from tip of the mastoid. The hypoglossal nerve loop was inferior to the digastric tendon in 73% of the cases. The hypoglossal nerves formed high loops in this study population. Caution should be exercised during surgical procedures in the neck. The study also revealed that the mastoid process is a reliable fixed landmark to locate the hypoglossal nerve.

Dental age estimation in a group of Kenyan children using Willems' method: a radiographic study.

BACKGROUND: Radiographic study of developing teeth provides a reliable indication of chronological age. In Kenya, dentists are often required to estimate age. However, there is a paucity of publications on the performance of dental age estimation methods. AIM: To determine the accuracy of Willems' method of dental age estimation. SUBJECTS AND METHODS: A cross-sectional study was done at The University of Nairobi Dental Hospital. Panoramic radiographs of children aged 3.00-16.99 years old were studied. Dental age was estimated according to Willems' method and compared to chronological age and the difference compared to zero using a t-test. RESULTS: Radiographs of 187 (47%) females and 214 (53%) males were analysed. Willems' method significantly over-estimated the mean overall age by -0.24 ± 1.17 years (p < .000). Age was over-estimated in girls by -0.10 ± 1.18 years (p = .254); however, age in boys was significantly over-estimated by -0.37 ± 1.14 years (p < .000). CONCLUSIONS: Willem's model over-estimated dental age slightly and the method performed better in estimating the age of girls compared to boys. The majority of the children had their age estimated within 1 year of their chronological age. This suggests that Willems' method is suitable for estimating the ages of individual children in Kenya.

Variant Anatomy of the Nasal and Labial Branches of the Infraorbital Nerve.

Comprehensive understanding of the variations in the branches of the infraorbital nerve (ION) is vital to the prevention of iatrogenic nerve injury and successful ION blockade during orbitozygomatic facial procedures. Only a few studies exist on the variant anatomy of the branching patterns of this nerve. This article provides a detailed description of the variations of the nasal and superior labial branches of the ION. This study was performed on 84 IONs by dissecting 42 formalin-fixed cadavers from the Laboratory of Topographic Anatomy, Department of Human Anatomy, University of Nairobi. The branches were exposed at their origin and followed to their termination. The findings included variant emergence patterns, anomalous course, and absence as well as extra branches. It was noted that the external nasal nerve was absent in 34.53% cases. There were common trunks between the internal and external nasal nerves and cases of communication between branches of these nerves were also noted. Accessory superior labial nerves were present in 9.52% of the nerves. This detailed study reveals additional variations in the emergence and branching pattern of the ION. Caution is imperative during orbitozygomatic facial surgery to prevent injury to these branches. These variations also underlie the lack of response to surgical treatment for trigeminal neuralgia and also the need for a filtration to achieve full anesthesia after ION block. In addition, the extra branches identified raise the prospects of using these nerves for grafting purposes if their precise patterns are determined.

Arterial blood supply variation in the anterior midline mandible: Significance to dental implantology.

BACKGROUND: Inter-foraminal implant placement poses a risk to the sublingual artery as it enters the mandibular midline lingual foramen. Lack of consensus on the source of this artery poses a dilemma to surgeons during management of haemorrhagic episodes. Determination of the exact source of this artery is therefore pivotal. METHODS: This was a cross-sectional descriptive study involving 34 adult human cadavers. The facial and lingual arteries were followed from the external carotid artery to determine whether they terminated as the sublingual artery. Statistical significance tests were done using the Mann-Whitney U test and Pearson product-moment correlation. RESULTS: There were 30 (88.2 %) males and 4 (11.8 %) females (male/female = 15:2) aged between 25 and 40 years. The origin of the sublingual artery was mainly from the lingual artery (73.5 %), the submental artery (17.6 %), or an anastomotic branch from the two arteries (8.9 %). The mean distance between the mandibular midline lingual foramen (MMLF) and the inferior border of the mandible was 15.58 mm (range 11.03-19.62 mm). The mean thickness of the mandible at the level of the MMLF was 10.89 mm (range 8.00-12.91 mm). No statistically significant difference was found between the two genders with regard to the morphometric measurements. CONCLUSIONS: The sublingual artery that enters the MMLF was found to be the sublingual artery as either a branch of the lingual artery (73.5 %), the submental artery (17.6 %) or an anastomosis of the lingual and submental arteries (8.9 %).

The surgical relevance of the anatomic position of the extraosseous mental nerve in a Kenyan population.

INTRODUCTION: Precise location of the mental nerve is important in implant surgery, administration of mental nerve block anaesthesia, and for osteotomy procedures. The position is known to show inter-population differences but data from sub-saharan region is scarce. METHODS: The point of emergence of 64 nerves was studied and data analyzed with Microsoft Excel 2010 and differences in side means compared using the paired one tailed student's t test. RESULTS: The location of left mental nerve was 2.85 (±0.38) cm, 1.42 (±0.33) cm, 1.77 (±0.46) cm while the right was 2.91(±0.47) cm, 1.38 (±0.3.1) cm, 1.71 (±0.46) cm from the mental symphysis, inferior border of mandible and cemento-enamel junction respectively. The differences in position between the right and left sides were not statistically significant (p<0.05 CI: 95%). It emerged inferior to but in line with the 2nd premolar in 57.8% of the cases, 2nd premolar-1st molar (25%) and inter-premolar junction (9.4%). Unique to this study, was the location of the MN at the canine (3.1%), and 1st molar (4.7%) positions. CONCLUSION: The aberrant position of the mental nerve seen in 42%, is an important consideration for tooth implants and placement of mandibular reconstruction plates.

Variations in emergence and course of the inferior palpebral nerve.

Comprehensive understanding of the anatomy of the inferior palpebral (IP) nerve is crucial to preservation of sensation in the inferior eyelid and conjunctiva. Iatrogenic injuries may occur during blepharoplasty, repair of orbitozygomatic fracture and other maxillofacial surgeries involving this region. Although several studies depict the anatomical variations of the main infraorbital nerve (ION), little information exclusive to the IP nerve exists. This study provides information on the additional variations of the ION with reference to the IP nerve. The study was performed on 84 IP nerves by dissection of 42 formalin-fixed cadavers from the laboratory of topographic anatomy, Department of Human Anatomy, University of Nairobi, Kenya. Each of the nerves were exposed at the emergence and followed to their termination. Variations encountered involved emergence, course, and even absence. Variant emergence was through an accessory infraorbital foramen, an infraorbital notch, and as a common trunk with the external nasal nerve. This nerve shows high anatomical variability that may account for the difficulties and complications encountered in clinical interventions. It is believed that this information will improve clinical management of conditions affecting the region of distribution of the IP nerve.

Keratocystic odontogenic tumours of the jaws and associated pathologies: a 10-year clinicopathologic audit in a referral teaching hospital in Kenya.

AIM: To establish the pattern of occurrence and the clinicopathological features of keratocystic odontogenic tumour (KCOT) over a 10-year period. MATERIALS AND METHOD: Patients from the University of Nairobi Dental Hospital treated for KCOT were included in the study over a 10-year period. The study highlights the demographic, clinico-radiological and histological features of these tumours. RESULTS: A total of 22 confirmed cases of KCOTs were recorded with equal gender prevalence; (M:F = 1.44:1). The age range of the patients was from 10 to 69 years with a peak in the second decade of life (mean = 27.5 yrs). Of the 22 cases, 15 (68.2%) occurred in the mandible of which eight (53.3%) involved the body, five (33.4%) the angle and ramus. Six (27.3%) occurred in the maxilla, and one (4.5%) was in both jaws and was associated with Gorlin-Goltz Syndrome. The most common presenting complaint in most patients was swelling 54.6%, and in 18.2% was incidental finding. Eight (36.4%) cases showed satellite cysts upon pathologic evaluation. Thirteen (59.1%) cases were managed by surgical excision, while nine (40.9%) were managed by enucleation. CONCLUSION: Based on the outcome of this study, KCOT present mostly in body, angle and ramus of the mandible and its peak is in the second decade of life.

Branching pattern of the extraosseous mental nerve in a kenyan population.

Knowledge of the branching pattern of the mental nerve is an important consideration during placement of tooth implants and reconstructive plates. It is known to display population variations and data for the same is scarce form the sub-Saharan region. With the recent increase in surgical interventions in the mandibular region in Kenya, a detailed description of mental nerve is warranted. A total of 64 mental nerves were dissected and branching pattern was noted. Single mental nerve was present in 60 (93.7%) cadavers while double mental nerves occurred in 3 (4.7%) and accessory in 1(1.6%). Most common pattern was bifurcation (39%) followed by trifurcation (34%), single (19%), and quadrification (8%). The double and triple branches were seen to further divide into two to three subbranches with diverse patterns. Side symmetry in branching was seen in four (6.25%). These are important anatomical considerations during placement of reconstructive plates for mandibular trauma and administration of mental nerve blocks.

Pattern of odontogenic and nonodontogenic cysts.

The jaws are host to a variety of cysts due in large part to the tissues involved in tooth formation. Odontogenic cysts (OCs) are unique in that they affect only the oral and maxillofacial region. There are few studies from sub-Saharan Africa. This study was aimed at describing the pattern of various types of cysts in the oral and maxillofacial region in a Kenyan population. This was done at the Departments of Oral and Maxillofacial Surgery and Oral Medicine and Pathology, University of Nairobi Dental Hospital. This was a retrospective audit. All histopathologic records were retrieved from 1991 to 2010 (19 years) and were counted. The following information was extracted and recorded in a data sheet: age, sex, and the type of cystic lesions. There were 194 cysts (4.56%) diagnosed of 4257 oral and maxillofacial lesions. Of these, 64.4% were from male and 35.6% were from female patients with an age range of 1 to 70 years (mean, 23.76 [SD, 14.05] years; peak and median of 20 years). The most common OCs (57.2%) were dentigerous and radicular, whereas the most common nonodontogenic cyst (42.8%) was nasopalatine duct cyst. Other soft tissue cysts reported were epidermoid, branchial, thyroglossal, dermoid, and cystic hygroma. Oral and maxillofacial cysts are not uncommon in this population, the majority being the OC, dentigerous cyst, followed by the nonodontogenic cyst, nasopalatine cyst. The cysts are male predominant and occur 10 to 15 years earlier compared with those in the white population.

One-stage treatment of acquired facial deformity caused by severe unilateral condylar hyperplasia.

Condylar hyperplasia (CH) is a rare and self-limiting process manifesting between the first and third decades of life. It causes facial asymmetry and derangement of occlusion. The management involves resection of the condylar head and orthognathic surgery followed by orthodontic treatment. We present a 33-year-old man with spontaneous onset of CH during a span of 10 years. This was managed with resection of the condyle alone, which dramatically improved facial asymmetry in addition to restoration of the occlusion within a few months of follow-up. Therefore, orthognathic surgery or orthodontic treatment was not needed.

Xeroderma pigmentosum: a review and case series.

Xeroderma pigmentosa (XP) is a condition inherited as an autosomal recessive trait and is characterized by photosensitivity, pigmentary changes, premature skin ageing and malignant tumour development resulting from the defect in DNA repair. The management of complications of XP, especially orofacial tumours entails an enormous surgical challenge to the clinicians. We present five cases of XP.